Whistle



FIG. 1 is an isometric view of a whistle showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof showing my design.

In the drawings, the broken lines depict portions of the whistle that form no part of the claimed design. 

CLAIM The ornamental design for a whistle, as shown and described. 